1. Field of the Invention
The present invention relates to a fuel filter for an automobile, the fuel filter having a filter element for filtering fuel and a fuel heater for heating the fuel.
2. Description of the Related Art
Japanese Patent Application Laid-open No. 61-160558 discloses a device having an electric heater provided in a fuel filter disposed in a fuel supply passage for supplying fuel (light oil) from a fuel tank to a diesel engine. The electric heater heats the fuel at a low temperature to prevent a filter element from clogging due to precipitation of a wax component contained in the fuel. The fuel filter includes a cylindrical heat-exchange chamber 22 accommodating therein the filter element 14 and a heating chamber 24, which is connected to a lower end of the heat-exchange chamber 22 and which accommodates the electric heater 16 therein. In the disclosed conventional device, the fuel is heated to a temperature wherein the wax component does not precipitate while passing through the heating chamber 24 and the heat-exchange chamber 22, thereby preventing the filter element 14 accommodated in the heat-exchange chamber 22 from clogging.
However, in the disclosed conventional device, the heating chamber 24 accommodating the electric heater 16 is connected to the lower end of the cylindrical heat-exchange chamber 22. Therefore, it is difficult for the heat generated by the electric heater 16 to be efficiently transferred to a wall surface of the heat-exchange chamber 22, leading to a possibility that the fuel is not sufficiently heated unless the capacity of the electric heater 16 is increased.